In order for a driver of a vehicle to visually check an environment around the driver's vehicle, there is a system that allows the driver to objectively and intuitively grasp the situation around the driver's vehicle by combining and converting a plurality of vehicle-mounted camera images into an image (overhead image) that views with a virtual line of sight that is a line of sight extending, for example, from the sky above the driver's vehicle to the driver's vehicle and displaying the image. An extended version disclosed is, for example, an image generation device that: turns a captured vehicle-mounted camera image into a three-dimensional space model without change; maps color information of the image onto the three-dimensional space model; converts the three-dimensional space model into an image seen from an arbitrary visual point; and displays the image.
If a three-dimensional shape (the shape of a cylinder, bowl or quasi-cylinder) made up of curved and flat surfaces is used as a model on which a camera image is projected just as the image generation device does, the advantage is that it is possible to view not only an overhead image around a vehicle but also all surrounding images including the sky at the same time.
What is also disclosed for such an image generation device is a technique of helping a driver check the safety in driving a vehicle by changing the images being displayed for the driver depending on the running state of the vehicle, i.e. the running speed, the steering angle of the wheel and the state of the results of detection by an object detection sensor.
As a result, it is possible to change images to be displayed that are supplied from a vehicle-mounted camera at a viewing position determined by a scene such as the operation of a vehicle.
The followings are disclosed as conventional techniques.    [Patent Document 1] Japanese Patent No. 3,286,306    [Patent Document 2] Japanese Patent No. 3,300,334